Electric motors and charging systems for vehicles need to be light weight, compact, and convenient. Induction motors are often used in vehicles. A separate inverter charging system is used to charge the battery from a utility power line, such as a 220VAC wall socket.
FIG. 1 shows a simplified schematic of a prior art induction motor and battery charging system 100. The stator 120 has three windings 120a, 120b, and 120c connected in a Y connection to a neutral node 125. An inverter 150 is connected between the battery 105 and the windings 120a, 120b, and 120c. The inverter 150 typically is controlled by a controller (not shown in FIG. 1) to convert the DC power from the battery 105 to AC power for the windings 120a, 120b, and 120c, to impart a torque on the rotor 140.
In this system 100, the battery 105 is charged by a separate AC to DC charger 110, which is connected to utility power 115. The charger 110 is connected across the battery 105.
With such a system, the charger 110 adds additional weight to the vehicle if integrated or separately carried on board the vehicle. If separate from the vehicle, the charger 110 might not be present, in the event it is needed for convenience or opportunity charging, or in case of an emergency.
What is needed is a charging system for electric vehicles that is light weight and convenient.